One year and many thousand SunSticks later, Cynthia VanRenterghem and Kerry VerMeulen are in line for an Innovation Award from the Small Business Association of Michigan.

SBAM announced that the two East Grand Rapids women are among "entrepreneurs that are driving Michigan's economy" and will be honored April 30 in Lansing at the annual SBAM "Michigan Celebrates Small Business" event.

Top honors at the SBAM event will go to the three owners of R.E.D. Stamp Inc., in Byron Center. Bruce D. DeBoer, James S. Rabourn and Robert L. Emaus were named the 2009 Michigan Small Business Persons of the Year and are now in contention for the national award in May.

Awards also will be presented to Harbor Industries Inc. in Grand Haven, and SoundOff Signal in Hudsonville.

Entrepreneurs VerMeulen and VanRenterghem formed Plumstone in 2007 to manufacture and market the SunStick, a device they developed for gardeners who want to measure the intensity of sunlight in particular areas of their garden.

VerMeulen said April 18 marked "exactly a year" since they sold the first SunSticks at a booth at the Bordine Nursery spring expo. Bordine is a major nursery and gardening supply company with several locations in southeast Michigan.

"We made 4,000 last year and those are all gone, and sold an additional 10,000 units this year," said VerMeulen. Some of those were a new SunStick product they recently developed for use inside homes.

She said Plumstone has received a design patent for SunStick, and they have applied for a utility patent. The SunStick sells for under $10.

VerMeulen said she originally came up with the concept for a gardening device to measure sunlight and joined forces with her friend, VanRenterghem, to develop it. VanRenterghem had previous experience in business ventures; she was a founding partner of Main Dish Kitchen, a food preparation franchise based in Holland.

Both women have four children and the kids went to the same elementary school in East Grand Rapids, plus the two families went to the same church.

"Our paths kept crossing," said VerMeulen.

VanRenterghem has an advanced degree in international economics and American foreign policy and worked in international trade. VerMeulen has a degree in natural resources and environmental sciences, and worked in hazardous waste site remediation.

Their company, Plumstone, now has one employee working in an East Beltline sales office that opened last November. Prior to that, the partners were working out of their homes — and sometimes in public places such as libraries, where they did research on business plans.

The SunStick is manufactured at Gazelle Prototype in Grand Haven, which designs and produces injection molded plastic components. The finished product is packaged by Display Pack in northeast Grand Rapids. A third company supplies the photo-sensitive component for the SunStick, but VerMeulen declined to identify that company, because "we prefer to keep them under wraps."

VerMeulen said the biggest hurdle they encountered in starting their business was "finding a way to make the product. When we first started, we didn't know how we were going to do it."

She said they knew they wanted to produce a simple device that would change colors to indicate sunlight levels.

"We didn’t want to go with something that was battery-operated or used a mini-processor," she said, because they felt that most gardeners would prefer a device that was "more organic." There was also the requirement for the device to operate throughout the day to get a complete reading of sunlight levels that vary with the movement of the sun across the sky, which can also involve intermittent shade.

A lot of testing went into the method of indicating light levels "and a lot of work to try to get it to make the color change in the way we wanted," she said. "We worked closely with the supplier on that."

Bill Van Harn at Gazelle Prototypes referred them to other sources of industrial information pertaining to photo-sensitive technology.

Another company that provided some advice was Pleotint LLC of West Olive, which produces photo-sensitive film for use on windows to control heat from the sun's rays.

"We found most people were very willing to help us if they could," said VerMeulen.

"Both Cynthia and I feel the fact that we are in Michigan really helped us make this product" because of "the manufacturing expertise and people we were able to speak to."

Even when a company didn't provide the services the Plumstone partners were looking for, "they knew someone they could send us on to," said VerMeulen.

She said that within 40 or 45 miles, "we found an incredible amount of expertise in what we were doing or a co-related field, and just felt that helped us so much."

Financing might have been a different story if Plumstone had come along one year later than it did. Financing came from a variety of sources: some of it was self-funded, some was provided by the Grand Angels investment group, and Fifth Third Bank provided a line of credit.

"Getting our funding from the Grand Angels was very important to us," said VerMeulen. "One of the things it enabled us to do was get an office — which we were really in need of by that point, having already manufactured" the product.

The line of credit from Fifth Third came through "a year ago, way before this whole credit crisis hit," said VerMeulen. "It was starting to get a little dicey even then, but nothing near like what was getting ready to happen," said VerMeulen.

Today, she said, Plumstone is "definitely profitable and growing."

The Small Business Association of Michigan holds an annual celebration of small business. This year the event at the Lansing Center will put a spotlight on more than 60 small businesses.

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